ectool: Upgrade to improved ioctl format

Support both old and new ioctl formats at the same time.
Auto-detect the ioctl format used by the kernel.

BUG=chromium:481710
BRANCH=None
TEST=Work on Samus with kernel 4.4 and 3.8/3.14/3.18

Change-Id: I31d7ce5b517b4b5af8e2b617e386c3cfd3276f20
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/331830
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>

1 files changed, 118 insertions, 3 deletions

diff --git a/util/comm-dev.c b/util/comm-dev.c
index 6e3cd42c10..94a5cdde52 100644
--- a/util/comm-dev.c
+++ b/util/comm-dev.c
@@ -3,10 +3,12 @@
  * found in the LICENSE file.
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
@@ -16,6 +18,7 @@
 #include "cros_ec_dev.h"
 #include "comm-host.h"
 #include "ec_commands.h"
+#include "misc_util.h"
 
 static int fd = -1;
 
@@ -49,6 +52,7 @@ static const char *strresult(int i)
 	return meanings[i];
 }
 
+/* Old ioctl format, used by Chrome OS 3.18 and older */
 
 static int ec_command_dev(int command, int version,
 			  const void *outdata, int outsize,
@@ -112,8 +116,112 @@ static int ec_readmem_dev(int offset, int bytes, void *dest)
 			      dest, bytes);
 }
 
+/* New ioctl format, used by Chrome OS 4.4 and later as well as upstream 4.0+ */
+
+static int ec_command_dev_v2(int command, int version,
+			     const void *outdata, int outsize,
+			     void *indata, int insize)
+{
+	struct cros_ec_command_v2 *s_cmd;
+	int r;
+
+	assert(outsize == 0 || outdata != NULL);
+	assert(insize == 0 || indata != NULL);
+
+	s_cmd = malloc(sizeof(struct cros_ec_command_v2) +
+		       MAX(outsize, insize));
+	if (s_cmd == NULL)
+		return -EC_RES_ERROR;
+
+	s_cmd->command = command;
+	s_cmd->version = version;
+	s_cmd->result = 0xff;
+	s_cmd->outsize = outsize;
+	s_cmd->insize = insize;
+	memcpy(s_cmd->data, outdata, outsize);
+
+	r = ioctl(fd, CROS_EC_DEV_IOCXCMD_V2, s_cmd);
+	if (r < 0) {
+		fprintf(stderr, "ioctl %d, errno %d (%s), EC result %d (%s)\n",
+			r, errno, strerror(errno), s_cmd->result,
+			strresult(s_cmd->result));
+		if (errno == EAGAIN && s_cmd->result == EC_RES_IN_PROGRESS) {
+			s_cmd->command = EC_CMD_RESEND_RESPONSE;
+			r = ioctl(fd, CROS_EC_DEV_IOCXCMD_V2, &s_cmd);
+			fprintf(stderr,
+				"ioctl %d, errno %d (%s), EC result %d (%s)\n",
+				r, errno, strerror(errno), s_cmd->result,
+				strresult(s_cmd->result));
+		}
+	} else {
+		memcpy(indata, s_cmd->data, MIN(r, insize));
+		if (s_cmd->result != EC_RES_SUCCESS) {
+			fprintf(stderr, "EC result %d (%s)\n", s_cmd->result,
+				strresult(s_cmd->result));
+			r =  -EECRESULT - s_cmd->result;
+		}
+	}
+	free(s_cmd);
+
+	return r;
+}
+
+static int ec_readmem_dev_v2(int offset, int bytes, void *dest)
+{
+	struct cros_ec_readmem_v2 s_mem;
+	struct ec_params_read_memmap r_mem;
+	int r;
+	static int fake_it;
+
+	if (!fake_it) {
+		s_mem.offset = offset;
+		s_mem.bytes = bytes;
+		r = ioctl(fd, CROS_EC_DEV_IOCRDMEM_V2, &s_mem);
+		if (r < 0 && errno == ENOTTY) {
+			fake_it = 1;
+		} else {
+			memcpy(dest, s_mem.buffer, bytes);
+			return r;
+		}
+	}
+
+	r_mem.offset = offset;
+	r_mem.size = bytes;
+	return ec_command_dev(EC_CMD_READ_MEMMAP, 0,
+			      &r_mem, sizeof(r_mem),
+			      dest, bytes);
+}
+
+/*
+ * Attempt to communicate with kernel using old ioctl format.
+ * If it returns ENOTTY, assume that this kernel uses the new format.
+ */
+static int ec_dev_is_v2(void)
+{
+	struct ec_params_hello h_req = {
+		.in_data = 0xa0b0c0d0
+	};
+	struct ec_response_hello h_resp;
+	struct cros_ec_command s_cmd = { };
+	int r;
+
+	s_cmd.command = EC_CMD_HELLO;
+	s_cmd.result = 0xff;
+	s_cmd.outsize = sizeof(h_req);
+	s_cmd.outdata = (uint8_t *)&h_req;
+	s_cmd.insize = sizeof(h_resp);
+	s_cmd.indata = (uint8_t *)&h_resp;
+
+	r = ioctl(fd, CROS_EC_DEV_IOCXCMD, &s_cmd);
+	if (r < 0 && errno == ENOTTY)
+		return 1;
+
+	return 0;
+}
+
 int comm_init_dev(const char *device_name)
 {
+	int (*ec_cmd_readmem)(int offset, int bytes, void *dest);
 	char version[80];
 	char device[80] = "/dev/";
 	int r;
@@ -138,10 +246,17 @@ int comm_init_dev(const char *device_name)
 		return 3;
 	}
 
-	ec_command_proto = ec_command_dev;
-	if (ec_readmem_dev(EC_MEMMAP_ID, 2, version) == 2 &&
+	if (ec_dev_is_v2()) {
+		ec_command_proto = ec_command_dev_v2;
+		ec_cmd_readmem = ec_readmem_dev_v2;
+	} else {
+		ec_command_proto = ec_command_dev;
+		ec_cmd_readmem = ec_readmem_dev;
+	}
+
+	if (ec_cmd_readmem(EC_MEMMAP_ID, 2, version) == 2 &&
 	    version[0] == 'E' && version[1] == 'C')
-		ec_readmem = ec_readmem_dev;
+		ec_readmem = ec_cmd_readmem;
 
 	/*
 	 * Set temporary size, will be updated later.